A plaintiff challenging the new health care law could derail a federal appellate ruling on its constitutionality because she bought health insurance from her employer last October.

Arguing on Wednesday before the Cincinnati-based 6th U.S. Circuit Court of Appeals, U.S. Solicitor General Neal Katyal said the case should be dismissed because one of the plaintiffs, Jann DeMars, purchased health insurance through her workplace, the New York Times reports.

Katyal said DeMars can’t demonstrate an imminent injury by the health care law’s requirement for individuals to buy health insurance or to pay a tax penalty. DeMars is a member of the Thomas More Law Center, which filed the suit.

A Justice Department court filing in the case says other plaintiffs didn’t file briefs on their standing or merely said the health insurance mandate would change their lifestyles, the Hill reported last month. One of the 6th Circuit judges hearing arguments, Judge Jeffrey Sutton, suggested the appeals court may have to remand for additional proceedings on standing.

Sutton and another judge on the panel are Republican appointees, while the third was appointed by a Democrat. The 6th Circuit is the second of three appeals courts scheduled to hear challenges to the law.

The Times called the 6th Circuit panel “arguably … less friendly” than the federal appeals panel that heard the first challenge to the health care law last month. The Wall Street Journal said the 6th Circuit gave the law a “mixed reception.”